scholarly journals Inhibitory activities of microalgal extracts against Epstein-Barr Virus (EBV) antigen expression in lymphoblastoid cells

2014 ◽  
Vol 66 (3) ◽  
pp. 1009-1024 ◽  
Author(s):  
Yih Koh ◽  
Wan Chu ◽  
Siew Phang ◽  
Shar Mohamed ◽  
Naidu Rakesh ◽  
...  

The inhibitory activities of microalgal extracts against the expression of three EBV antigens, latent membrane protein (LMP)1, Epstein-Barr nuclear antigen (EBNA)1 and Z Epstein-Barr reactivation activator (ZEBRA) were assessed by immunocytochemistry. The observation that the methanol extracts and their fractions from Ankistrodesmus convolutus, Synechococcus elongatus and Spirulina platensis exhibited inhibitory activity against EBV proteins in three Burkitt?s lymphoma cell lines at concentrations as low as 20 ?g/ml suggests that microalgae could be a potential source of antiviral compounds against EBV.

2004 ◽  
Vol 32 (5) ◽  
pp. 731-732 ◽  
Author(s):  
M.N. Holowaty ◽  
L. Frappier

USP7 (also called HAUSP) is a de-ubiquitinating enzyme recently identified as a key regulator of the p53–mdm2 pathway, which stabilizes both p53 and mdm2. We have discovered that the Epstein–Barr nuclear antigen 1 protein of Epstein–Barr virus binds with high affinity to USP7 and disrupts the USP7–p53 interaction. The results have important implications for the role of Epstein–Barr nuclear antigen 1 in the cellular immortalization that is typical of an Epstein–Barr virus latent infection.


Viruses ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 766
Author(s):  
Richmond Ayee ◽  
Maame Ekua Oforiwaa Ofori ◽  
Emmanuel Ayitey Tagoe ◽  
Sylvester Languon ◽  
Kafui Searyoh ◽  
...  

Nasopharyngeal cancer (NPC) is associated with Epstein Barr virus (EBV) infection. However different viral strains have been implicated in NPC worldwide. This study aimed to detect and characterize EBV in patients diagnosed with NPC in Ghana. A total of 55 patients diagnosed with NPC by CT scan and endoscopy were age-matched with 53 controls without a known oncological disease. Venous blood was collected from the study participants and DNA extracted from the blood samples. Detection of EBV and genotyping were done by amplifying Epstein Barr nuclear antigen 1 (EBNA-1) and Epstein Barr nuclear antigen 2 (EBNA-2), respectively, using specific primers. Viral load in patients and controls was determined using real-time polymerase chain reaction. EBV positivity in controls (92%) was significantly greater than that of NPC patients (67%) (χ2 = 19.17, p < 0.0001), and viral infection was independent of gender (χ2 = 1.770, p = 0.1834). The predominant EBV genotypes in patients and controls were genotype 2 (52%) and genotype 1 (62%), respectively. Median EBV load was significantly higher in NPC patients than the control group (p < 0.01). In summary, prevalence of EBV genotype 2 infection was higher in NPC patients than the control group. Assessment of EBV load may be used as a biomarker for the diagnosis of NPC.


2013 ◽  
Vol 20 (6) ◽  
pp. 747-750 ◽  
Author(s):  
Jonatan Salzer ◽  
Hans Stenlund ◽  
Peter Sundström

The multiple sclerosis (MS) risk factors smoking and remote Epstein-Barr virus (EBV) infection have been suggested to interact statistically, but the results are conflicting. In a prospective study on 192 MS cases and 384 matched controls, we analysed levels of cotinine as a marker of smoke exposure, and Epstein-Barr Nuclear Antigen-1 antibody reactivity. We assessed interaction on the additive and multiplicative scales, and estimated the effects of the risk factors across strata of each other. The results suggest that a negative interaction may be present in samples drawn at a young age, and a positive interaction among older subjects.


Blood ◽  
1996 ◽  
Vol 88 (8) ◽  
pp. 3147-3159 ◽  
Author(s):  
F Pomponi ◽  
R Cariati ◽  
P Zancai ◽  
P De Paoli ◽  
S Rizzo ◽  
...  

Natural and synthetic retinoids have proved to be effective in the treatment and prevention of various human cancers. In the present study, we investigated the effect of retinoids on Epstein-Barr virus (EBV)-infected lymphoblastoid cell lines (LCLs), since these cells closely resemble those that give rise to EBV-related lymphoproliferative disorders in the immunosuppressed host. All six compounds tested inhibited LCL proliferation with no significant direct cytotoxicity, but 9-cis-retinoic acid (RA), 13-cis-RA, and all-trans-RA (ATRA) were markedly more efficacious than Ro40–8757, Ro13–6298, and etretinate. The antiproliferative action of the three most effective compounds was confirmed in a large panel of LCLs, thus appearing as a generalized phenomenon in these cells. LCL growth was irreversibly inhibited even after 2 days of treatment at drug concentrations corresponding to therapeutically achievable plasma levels. Retinoid-treated cells showed a marked downregulation of CD71 and a decreased S-phase compartment with a parallel accumulation in Gzero/ G1 phases. These cell cycle perturbations were associated with the upregulation of p27 Kip1, a nuclear protein that controls entrance and progression through the cell cycle by inhibiting several cyclin/cyclin-dependent kinase complexes. Unlike what is observed in other systems, the antiproliferative effect exerted by retinoids on LCLs was not due to the acquisition of a terminally differentiated status. In fact, retinoid-induced modifications of cell morphology, phenotype (downregulation of CD19, HLA-DR, and s-Ig, and increased expression of CD38 and c-Ig), and IgM production were late events, highly heterogeneous, and often slightly relevant, being therefore only partially indicative of a drug-related differentiative process. Moreover, EBV-encoded EBV nuclear antigen-2 and latent membrane protein-1 proteins were inconstantly downregulated by retinoids, indicating that their growth-inhibitory effect is not mediated by a direct modulation of viral latent antigen expression. The strong antiproliferative activity exerted by retinoids in our experimental model indicates that these compounds may represent a useful tool in the medical management of EBV-related lymphoproliferative disorders of immunosuppressed patients.


Science ◽  
1983 ◽  
Vol 220 (4604) ◽  
pp. 1396-1398 ◽  
Author(s):  
K Hennessy ◽  
M Heller ◽  
V van Santen ◽  
E Kieff

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